In general, multiple semiconductor integrated circuits formed on a semiconductor wafer undergo an electric test before being separated into respective chips to determine whether or not they are manufactured in accordance with the specification. In this electric test, a probe assembly such as a probe card provided with a plurality of probes to be connected to electrodes of the respective semiconductor integrated circuits on the semiconductor wafer as a device under test is used (for example, refer to Patent Literature 1). The semiconductor wafer is connected to a tester via this probe card as the electrodes of the respective semiconductor integrated circuits are connected to the corresponding probes of the probe card.
More specifically, such a test is performed under a certain measuring temperature in accordance with a use environment of the integrated circuits. Accordingly, in the conventional probe assembly, a chuck as a working table on which the semiconductor wafer is held is provided with a heat source and is heated by heating of the heat source, for example, and a probe base plate is heated along with heating of the chuck.
When the chuck is held at the certain measuring temperature, the semiconductor wafer on the chuck is also held around an approximate temperature to that of the chuck. However, the probe base plate of the probe card is located over the semiconductor wafer as the device under test and is basically heated by radiation heat from the chuck. Hence, even when the temperature of the probe base plate reaches a stable achieving temperature (saturated temperature), the temperature of the semiconductor wafer reaching the desired measuring temperature and the aforementioned achieving temperature of the probe base plate are not equal and have a temperature difference therebetween, and the latter is lower than the former.
This temperature difference causes an expansion difference exceeding a tolerance between an expansion amount of the device under test when the temperature reaches the measuring temperature from a room temperature and an expansion amount of the probe base plate when the temperature reaches the achieving temperature from the room temperature even when the probe base plate having an equal linear expansion coefficient to that of the semiconductor wafer as the device under test is used. The expansion difference exceeding the tolerance brings about a connection failure between the corresponding probes and electrodes. Under such circumstances, to reduce the expansion difference caused by the temperature difference between the measuring temperature of the device under test and the achieving temperature of the probe base plate, the probe base plate having a larger linear expansion coefficient than that of the device under test is normally used for the purpose of compensating the aforementioned temperature difference. Under such conditions, the respective probes are provided on the probe base plate so that the probes may be located at positions of electrode pads of the device under test which is at the measuring temperature when the temperature of the probe base plate reaches the achieving temperature.
Accordingly, as long as the probe card set for the certain measuring temperature is used at the set measuring temperature, the electrodes of the device under test and the corresponding probes of the probe card can be connected at the measuring temperature within the tolerance, and thus an appropriate electric test can be performed.
However, even a semiconductor wafer having formed thereon semiconductor integrated circuits to be manufactured in an equal standard requires a test under a different measuring temperature from the aforementioned certain measuring temperature in some cases due to a difference in use environment of the semiconductor integrated circuits.
In such a case, even when the device under test is to be tested at the different measuring temperature with use of the probe card set for the certain measuring temperature, the set measuring temperature is different from the different measuring temperature, and thus a difference between each probe position of the probe base plate and each electrode position of the device under test exceeds a range of the tolerance in some cases.
Accordingly, in a conventional case, a probe card in which probe positions are set in accordance with a measuring temperature needs to be prepared per measuring temperature even for a semiconductor wafer having formed thereon semiconductor integrated circuits to be manufactured in an equal standard.
Meanwhile, providing the probe base plate with a controllable heat source in addition to the heat source provided in the chuck can be thought (for example, refer to Patent Literature 1 and 2). According to this thought, since the temperature of the device under test and the temperature of the probe base plate can be controlled individually so that the probes of the probe base plate and the corresponding electrodes of the device under test that are under the desired measuring temperature may be located within the tolerance, it is possible to test the same device under test at two different measuring temperatures with use of one probe card.
However, in this case, since the heat source adapted to keep the temperature uniformly over the entire area needs to be arranged in the probe base plate provided with wiring circuits, complication of a structure of the probe base plate is inevitable.